It should probably be pointed out that the Legendary Weapons and Armor section doesn't actually talk about adding flat +X bonuses outside of the Enchanted Qualities (aside from a sidebar on weapons/armor with a simple +1 that don't quite qualify as legendary). It may assume that any +X to hit, damage, and/or AC is intended to come from the Enchanted Qualities alone.

But yeah, if you're giving a scaling weapon that unlocks additional qualities as the bearer levels up and you're planning on having a + bonus on it in addition to that, you should probably consider that bonus appropriate the bearer's level as well - if you intended the weapon to have a +3 when it has all 3 properties but you're giving it when the bearer can only have 1 property, start it at +1 and let it scale up.

From P. 127 of the LMG
"Artefact Bonus
The bearer of a Wondrous Artefact enjoys a bonus to all
ability checks made using the corresponding skill.
• The Artefact Bonus is equal to the hero’s Proficiency
Bonus."

From P. 127 of the LMG
"Artefact Bonus
The bearer of a Wondrous Artefact enjoys a bonus to all
ability checks made using the corresponding skill.
• The Artefact Bonus is equal to the hero’s Proficiency
Bonus."

From P. 127 of the LMG
"Artefact Bonus
The bearer of a Wondrous Artefact enjoys a bonus to all
ability checks made using the corresponding skill.
• The Artefact Bonus is equal to the hero’s Proficiency
Bonus."

That's the + to ability checks, not the + to Hit and Damage rolls.

IMO, that is a matter of interpretation. Does it actually say in 5E anywhere that hitting a target is not an ability roll?

IMO, that is a matter of interpretation. Does it actually say in 5E anywhere that hitting a target is not an ability roll?

Yes. Ability Checks, page 174 of Player's Handbook: "An ability check tests a character’s or monster’s innate talent and training in an effort to overcome a challenge. The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure."

Also, at page 6, The d20, it makes a specific distinction between ability checks, attack rolls, and saving throws: "[...]Ability checks, attack rolls, and saving throws are the three main kinds of d20 rolls, forming the core of the rules of the game."

So in synthesis an Ability check is any roll that is linked to an Ability score and that is not an attack roll or a saving throw. This includes all skill checks and the Initiative roll.

P.S. A side note that most players (and DMs) do not realize: since Initiative rolls are ability checks that don't already include your proficiency bonus, Warden's (and Bard's) Jack-of-all-trades feature technically applies to Initiative rolls as well.

IMO, that is a matter of interpretation. Does it actually say in 5E anywhere that hitting a target is not an ability roll?

Yes. Ability Checks, page 174 of Player's Handbook: "An ability check tests a character’s or monster’s innate talent and training in an effort to overcome a challenge. The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure."

Also, at page 6, The d20, it makes a specific distinction between ability checks, attack rolls, and saving throws: "[...]Ability checks, attack rolls, and saving throws are the three main kinds of d20 rolls, forming the core of the rules of the game."

So in synthesis an Ability check is any roll that is linked to an Ability score and that is not an attack roll or a saving throw. This includes all skill checks and the Initiative roll.

P.S. A side note that most players (and DMs) do not realize: since Initiative rolls are ability checks that don't already include your proficiency bonus, Warden's (and Bard's) Jack-of-all-trades feature technically applies to Initiative rolls as well.

Fair enough. The example on p. 174 by definition (fighting requires innate talent and training) is not really that clear, but p. 20 does make clear distinction.

However, I think that the prof bonus for legendary weapons is the way to go . It just adds a certain more flavor to a weapon, makes it a part of the character, which in the end will stop the endless upgrading of weapons that usually occurs in a D&D game. This would make the second best magic weapons system I've seen in an RPG.

While it would certainly allow the weapon to level up, it would quite frankly be too much. +2 to +6 to hit and damage blows Fifth Edition's Bounded accuracy right out of the water. Even the Most Powerful Artifacts in the 5e Dungeon Master's Guide never have more than a +3 to Hit and Damage.